Detoxification of the Liver In PSC (Dolphin)

This study is a clinical trial being done to investigate the efficacy of drug BRS201 (hydroxocobalamin) as a treatment in patients with primary sclerosing cholangitis. Participation in this study will take 8 weeks long and the study is structured as a cross-over study in which participants will take the study drug for 4 weeks and a placebo drug for 4 weeks in a randomized order in the form of an oral medication. Participation may also involve receiving an IV dose of the medication. The study will require participants to attend 9 study visits, all of which will be remote. Participation will involve taking an oral medication twice daily, tracking the medication in a log, and getting blood drawn and giving a stool sample for a few lab tests throughout the study. For the lab tests, a research nurse will visit the participant in-home for the convenience of the participant.